The invention relates to a common rail fuel injection system for a multi-cylinder internal combustion engine having magnetic valve controlled direct injection fuel injection valves with a fuel admission passage leading in each valve housing to a spring-loaded nozzle needle and including a control piston with an integral control valve by which the fuel admission passage can be closed. The valve housing includes a spring space with a spring engaging the nozzle needle so as to bias it onto a nozzle needle seat, a control space disposed on the backside of the control piston which is exposed to system pressure and a cooperating magnetic valve by which the control space can be placed in communication with a pressure relief passage and by which, at the same time, the passage leading to the nozzle needle can be opened, the passage being also in communication with the pressure release passage by way of a throttled communication passage.
DE 196 12 738 A1 discloses such a common rail injection system with magnetic valve controlled fuel injection valves. It includes a control piston with an integrated valve which is guided in two housing parts and is in communication with the backside of the nozzle needle by way of the spring space. The valve is formed by an annular conical seat surface which extends downwardly from the control piston into an intermediate space for engagement with a corresponding conical valve seat formed on the housing.
It is the object of the present invention to provide a fuel injection valve having means by which the injection process can be influenced and the overall efficiency of the injection system can be improved.